This is a slice of my philosophical, lay scientific, musical, religious skepticism, and poetic musings. (All poems are my own.)
The science and philosophy side meet in my study of cognitive philosophy; Dan Dennett was the first serious influence on me, but I've moved beyond him.
The poems are somewhat related, as many are on philosophical or psychological themes. That includes existentialism and questions of selfhood, death, and more. Nature and other poems will also show up here on occasion.

Wednesday, February 15, 2012

Identical twins aren't so identical, not even their brains

That's been known to be true for some time. Depending on when the
single fertilized egg divided, identical twins can have separarate
amniotic sacs, umbilical cords and placentas, the same sac, the same
cord as well, or even the same placenta.

And now, we're learning that identical twins may not have entirely the same genetic makeup, not even in brain cells. As a result, twin studies for illnesses, behavior, etc., may
be called into a bit of question, and future twin studies more
carefully controlled for subjects.

At the same time, the authors
occasionally slip into quasi-teleological language while wondering why
evolution "allows" this. Their proposed answer as to why this may happen
is interesting, but could serve to have that language nuanced better.
Also, even if you allow for the teleological/personifying language, that
may not be the reason why this happens; maybe epigenetic events are at
least partially involved, even with identicals. After all, they don't
share 100 percent the same environment.

And, it may turn out that on a statistical average, such
transposition isn't favorable or unfavorable, and that we're talking
about a ramped-up genetic drift. Or maybe more modest transposition was
more favorable, and now, the degree of favorability has lessened. From
what little I know, genetic studies like this are kind of like studying
individual frames, or at best, snippets, from a movie, when the backdrop
for the movie may have been radically different at another point.